The Norwegian Environment Agency has released haunting images of reindeer—including 70 calves—that seemingly fell over where they stood in the grasses of Hardangervidda, the largest high mountain plateau in northern Europe.

While specifics on the lightning strike are still unknown at this time, it’s likely that the dead reindeer were a herd that huddled together to weather a severe thunderstorm that rolled through the area on Friday.

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The park where the animals died spans some 8,000 square kilometers (3,088 square miles) and is home to 10,000 to 11,000 wild reindeer.

“I’ve heard of groups of cow [getting killed] when it strikes the ground,” says Steve Goodman, a scientist with the National Oceanographic and Atmospheric Administration’s Satellite Service. “The lightning can spread for hundreds and hundreds of meters, for sure.”

But Goodman notes that Norway is not particularly prone to severe lightning. Satellite data from NASA’s Global Hydrology Research Center show that in an average year, southern Norway sees fewer than one lightning strike per square kilometer.

In contrast, the world’s biggest lightning hot spot, Venezuela’s Lake Maracaibo, gets struck more than 232 times per square kilometer in an average year—and endures nighttime thunderstorms 297 days of the year.